Tracking issue for std::process::id

[tmccombs]

The standard library provides a way to get the process id of a child process with std::process::Child::id(), but doesn't have any way to get the current processes id (the equivalent of getpid).

It is possible to do this with libc::getpid, but it seems to me that this should be something that is part of the standard library, especially since it already has cross-platform support for process ids of child processes.

[sfackler]

Seems reasonable to add!

[retep998]

GetCurrentProcessId on Windows.

[sfackler]

Reopening as the tracking issue.

[EdSchouten]

While porting Rust over to CloudABI, a sandboxed UNIX-like runtime environment, I ran into the issue that there is no way for me to implement this function. As we're aiming to use CloudABI in distributed settings, there is no traditional 16/32-bit process identifier. Instead, processes may be identified by a UUID. This is useful, as integer process identifiers can easily collide when dealing with many instances of a job (due to the birthday paradox).

As this function was only introduced recently, would it still be possible to alter it to return an opaque, but displayable data type instead? That said, almost all of the other functions provided by this module are also broken on CloudABI. The traditional fork()/execve() model doesn't lend well to sandboxing. Maybe it makes more sense to disable std::process on CloudABI entirely.